The present exemplary embodiment relates to masts. It finds particular application in conjunction with tilting of telescoping masts for antennas, lights and other payloads, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications.
Telescoping masts generally include multiple tube or lattice structure sections that are configured to telescope or nest within each other. A drive system is typically configured to deploy and/or retract the tubes between extended and retracted configurations. Locks or latches may be used to lock each tube to its adjacent tube or tubes when in the extended configuration.
Military and commercial mast users often have a need to transport a telescoping mast to the location where it will be deployed. It is often desired to have these masts deployed and ready for use immediately upon arriving on location. In addition, some mast systems would be unable to fit in aircraft or trucks, or clear bridges and other overhead encumbrances without bringing the mast to a horizontal position for transport. One means to bring the mast to a horizontal position is by using a tilting mechanism. A tilting mechanism can be manual or automated. In cases where the masts and payloads are large or where time to readiness is critical an automated version is desired.
One version of an automated tilting mechanism uses an actuator to provide a rotational moment to tilt the mast which is mounted in a pivoting cradle. This rotational moment can be provided by an electromechanical, pneumatic or a hydraulic actuator, or through other mechanical means using a motor and gears, etc. An automated tilting mechanism also generally includes a locking mechanism to “lock” the pivoting cradle with the mast in the horizontal and vertical positions. When the mast carrying cradle is in the horizontal position it needs to be secured to avoid damage to the mast or payload during transportation. When the mast carrying cradle is in the vertical position it needs to be secured to provide a stable platform for the payload to function properly.
One approach to lock the tilting cradle carrying a mast in either position is by moving a large pin into a bushing that is securely fastened to the automated tilt mechanism base. To prevent rotational movement of the cradle and mast due to mast payload induced pivoting and torsional loads on the mast, four locking actuators have generally been needed, each actuator configured to a locking pin into and out of engagement with a lock hole.